SerialICE

SerialICE is a flexible, software based system software debugger. Based on the open source processor emulator Qemu, SerialICE allows you to log and intercept hardware accesses of your firmware and single step your firmware with the GNU debugger. After a couple of quiet years on the development front, it has now adopted new filtering subsystem.

coreboot-SerialICE integration

As of now a set of patches has been proposed that would unify the codebase of SerialICE and coreboot.
Apart from the maintenance benefits this also avoids the duplication of initialisation code since they could share the same base.